rails/rails — pull request #4870 by sikachu (2012-02-03 17:12:07+00:00)
Title: Fix override API response bug in respond_with

Default responder was only using the given respond block when user
requested for HTML format, or JSON/XML format with valid resource. This
fix the responder so that it will use the given block regardless of the
validity of the resource. Note that in this case you'll have to check
for object's validity by yourself in the controller.

See #4796. This is for 3-2-stable.